A need has emerged in mobile devices for a powered, digital headphone capability to enable advanced signal processing functionality such as ANC (active noise cancellation), DSP (Digital Signal Processor) based EQ tuning, bi-directional interactivity with the mobile device, and possible inclusion of sensors for monitoring biometrics and the environment.
A popular conventional interface that provides power and digital connectivity in computers and electronic devices is the Universal Serial Bus (USB). The use of USB in mobile devices, however, has evolved to include 480 Mbps USB 2.0 or higher and advanced hub capability. Typically, the power consumption to support the full USB standard and the high speed interface is too high for the low power audio streaming modes that most mobile platforms support. Further, the USB is often turned off during low power operating modes, such as when only the headphones are used. Therefore, in order to support a powered, digital headphone capability, a new approach is needed.
Embodiments of the invention address these and other limitations of the prior art.